The overall objective of the proposed research program is to throw more light, through biochemical-pharmacological studies, on the mechanisms underlying the relationships between the cations Ca2++, Na+ and K+ and their transport processes and the neurotransmitter-induced changes in phospholipids-, phosphoproteins- and ATP phosphate turnover in the iris. To achieve this we propose to carry out the following experiments: 1. Investigate the kinetics of the effects of the neurotransmitters, acetylcholine and norepinephrine, pharmacological agents and cation-ionophores on Na+- and Ca2++-transport. 2. Investigate the mechanism(s) of the observed effects of Na+, K+ and Ca2++ on the neurotransmitter-induced changes in: a) phospholipid-phosphate turnover. b) Phosphoprotein phosphate turnover. c) ATP phosphate turnover. 3. Investigate the types of receptors which may mediate the neurotransmitter-induced changes in phosphoprotein-phosphate turnover. 4. Investigate the relationships between the neurotransmitter-induced postsynaptic permeability changes of cations and phospholipid- and phosphoprotein phosphate turnover and metabolic energy. 5. Investigate the effects of the cations Na+, K+ and Ca2+ on the activities of the key enzymes which are presumably involved in: a) Phospholipid-phosphate turnover. b) Phosphoprotein-phosphate turnover. c) Cation-transport processes. Our proposed studies will, hopefully, throw more light on the following: a) Yield relevant information with regard to the role of phospholipids and phosphoproteins and their relationship to muscarinic cholinergic and alpha-adrenergic mechanisms. b) Nature of the involvement of phospholipids and phosphoproteins in neurotransmitter-induced membrane permeability, and illumination of the phosphate rearrangements in regulation of membrane permeability during receptor activation. c) Mechanism of action of pharamacological agents on smooth muscle of the eye. d) Mechanism of aqueous humor formation, which is involved in regulating intraocular pressure.